A filter cartridge for operatively coupling to an appliance interface to treat a fluid, such as water, being supplied to the appliance. The interface comprises a bypass valve for actuating the interface between a bypass mode in which the fluid flowing through the interface does not flow through the filter cartridge and a treatment mode in which the fluid flowing through the interface is directed through the filter cartridge for treatment by the filter cartridge. The filter cartridge comprises a cartridge housing having a first end and a second end and extending along a housing longitudinal axis through the first end and the second end. A filter media is contained within the cartridge housing between the first end and the second end. The filter cartridge also has a first end cap on the first end of the cartridge housing and a second end cap on the second end of the cartridge housing. A bypass valve actuator is attached to the cartridge housing and extends distally to an actuator distal end. The bypass valve actuator is configured such that the actuator distal end actuates the bypass valve of the interface as the filter cartridge is coupled to interface.